Air supply system

Abstract

An air supply system ( 200, 300 ) for providing a clean air flow ( 250 ) in a room ( 1 ) is provided. The air supply system ( 200, 300 ) comprises a first air supply section ( 120 ) through which a first flow of clean air is supplied with a lower temperature than the temperature of the ambient air in the room ( 1 ), and a second air supply section ( 230 ) through which a second flow of clean air is supplied. The first air supply section ( 120 ) is arranged to form a gravitationally induced downward flow, whereas the second air supply section ( 230 ) is arranged to adjust the velocity (vi) of the second flow of clean air when entering the second air supply section ( 230 ) to a predetermined velocity (v 2 ), and is adapted to direct the second flow of clean air downwards. A method ( 600 ) for providing a clean air flow in a room is further provided.

The invention claimed is: 
     
       1. An air supply system for providing a clean air flow in a room, the air supply system comprising:
 a first air supply section through which a first flow of clean air is supplied with a lower temperature than the temperature of the ambient air in the room, 
 a second air supply section through which a second flow of clean air is supplied, 
 wherein the first air supply section is arranged to brake the initial velocity (v 1 ) of the first flow of clean air when entering the first air supply section, such that the initial velocity (v 1 ) of the first flow of clean air is reduced such that the velocity of the clean air leaving the first air supply section is essentially zero in a position below and at a vicinity of the first air supply section, whereby the first flow of clean air thereafter forms a gravitationally induced downward flow, 
 wherein the second air supply section comprises an inner air permeable layer, said second air supply section being arranged to adjust, at least by adjusting the resistance of the inner air permeable layer, the velocity (v 1 ) of the second flow of clean air when entering the second air supply section to a predetermined velocity (v 2 ), and adapted to direct the second flow of clean air downwards, 
 wherein the first flow of clean air and the second flow of clean air together make up a clean air flow, 
 wherein the predetermined velocity (v 2 ) is selected such that the clean air flow has essentially the same velocity (v 3 ) throughout an entire cross-section of the clean air flow, as seen transverse the downward direction, of the clean air flow at a specific level, the specific level being a working height for activities in a work area of the room which the clean air flow covers, and 
 wherein the first air supply section and the second air supply section are situated in the ceiling in the room, the first air supply section at least partly surrounding the second air supply section. 
 
     
     
       2. The air supply system according to  claim 1 , wherein the second flow of clean air has the same temperature as the first flow of clean air. 
     
     
       3. The air supply system according to  claim 1 , wherein the second air supply section comprises air outlets formed in an air supply membrane. 
     
     
       4. The air supply system according to  claim 3 , wherein the air outlets in the air supply membrane are formed as a honeycomb structure. 
     
     
       5. The air supply system according to  claim 1 , wherein the first air supply section comprises at least one air supply membrane formed by an air permeable body. 
     
     
       6. The air supply system according to  claim 5 , wherein the first air supply section comprises a plurality of air supply membranes, and wherein air spoilers are disposed between each pair of mutually adjacent air supply membranes of the first air supply section. 
     
     
       7. The air supply system according to  claim 1 , further comprising a temperature controller arranged to adjust the temperature of the clean air forming the first flow of clean air and/or the second flow of clean air, the adjustment being based on the temperature of the ambient air in the room as measured by one or more temperature sensors located in the ambient air in the room. 
     
     
       8. The air supply system according to  claim 1 , wherein the first air supply section is ring-shaped and surrounds the second air supply section. 
     
     
       9. The air supply system according to  claim 1 , wherein the clean air flow is provided between the first and second air supply sections and a work area in the room. 
     
     
       10. The air supply system according to  claim 9 , wherein the room is an operating theatre. 
     
     
       11. The air supply system according to  claim 1 , wherein the first air supply section and the second air supply section are supplied with a common flow of clean air, said common flow of clean air having an initial velocity (v 1 ) and temperature (T 1 ). 
     
     
       12. The air supply system according to  claim 1 , wherein the first air supply section comprises a plurality of air supply membranes, and wherein air spoilers are disposed between each pair of mutually adjacent air supply membranes of the first air supply section. 
     
     
       13. The air supply system according to  claim 1 , wherein the room is an operating theatre. 
     
     
       14. A method for providing a clean air flow in a room, the method comprising:
 supplying a first flow of clean air through a first air supply section, the first flow of clean air having a lower temperature than the temperature of the ambient air in the room, 
 braking, by the first air supply section, the initial velocity of the first flow of clean air when entering the first air supply section such that the initial velocity (V 1 ) of the first flow of clean air is reduced so the velocity of the clean air leaving the first air supply section is essentially zero at a position below the air supply section, whereby the first flow of clean air thereupon forms a gravitationally induced downward flow, 
 supplying a second flow of clean air through a second air supply section, 
 adjusting, at least by an inner permeable layer of the second air supply section, the velocity of the second flow of clean air when entering the second air supply section to a predetermined velocity (V 2 ), and 
 directing, by the second air supply section, the second flow of clean air downwards to cooperatively constitute a clean air flow, 
 wherein the clean air flow is the same velocity (V 3 ) horizontally across the entire clean air flow at the level of the working height of the activities of the room; 
 wherein the first air supply section and the second air supply section are situated in the ceiling in the room, the first air supply section at least partly surrounding the second air supply section.